How do you change the thermostat on a 99 Honda passport?

To change the thermostat on a 1999 Honda Passport, first, ensure the engine is cool and disconnect the negative battery cable. Drain the coolant from the radiator and remove the upper radiator hose connected to the thermostat housing. Unbolt the thermostat housing to access the thermostat, remove the old thermostat, and clean the mating surfaces. Install the new thermostat, reassemble the housing and hose, refill the coolant, and reconnect the battery.